Central condo (Sukhumvit Soi 7) to stay if you want to explore the city center of Bangkok. Area is obviously a little busier than areas further outside but I did not have problems with noise at all since you walk about 5 mins to the main road. The place itself has everything you can think of, including a washing machine, micro wave and hair dryer. The internet worked reliably and was fast. There were some tiny flies present in the condo but I have now seen this in various (clean) places in Bangkok and they did not really bother me at all. After all a great stay in the city center and you reach the BTS station quickly which was an important point for me. Recommended!